User Story:

As a (user persona), I want to be able to:

• Allow the user to select N4A instances (this should probably only be used for compute nodes)
• Capability 2
• Capability 3

so that I can achieve

• N4A compute instances in the cluster
• Outcome 2
• Outcome 3

Acceptance Criteria:

Description of criteria:

• Upstream documentation
• Point 1
• Point 2
• Point 3

(optional) Out of Scope:

• N4A instances should only be available for compute nodes (Discussion is still open).
• N4A instances have the following disk types: hyperdisk-balanced, hyperdisk-balanced-high-availability, and hyperdisk-througput.

Engineering Details:

• update pkg/types/gcp/machinepools.go to include n4a instances 

  "n4a": {HyperDiskBalanced}, 

• update pkg/asset/installconfig/gcp/validation.go to include n4a instances in the accepted arm types: 

  acceptedArmFamilies := sets.New("c4a", "n4a", "t2a") 

This requires/does not require a design proposal.
This requires/does not require a feature gate.